Polyphenol bioactivity evolution during the spontaneous fermentation of vegetal by-products

Regulating the physicochemical, structural characteristics and digestibility of potato starch by complexing with different phenolic acids

The effects of ferulic acid (FA), protocatechuic acid (PA), and gallic acid (GA) on the physicochemical characteristics, structural properties, and in vitro digestion of gelatinized potato starch (PS) were investigated. Rapid viscosity analysis revealed that the gelatinized viscosity parameters of PS decreased after complexing with different phenolic acids. Dynamic rheology results showed that phenolic acids could reduce the values of G' and G″ of PS-phenolic acid complexes, demonstrating that the addition of phenolic acids weakened the viscoelasticity of starch gel. Fourier-transform infrared spectra and X-ray diffraction results elucidated that phenolic acids primarily reduced the degree of short-range ordered structure of starch through non-covalent interactions. The decrease in thermal stability and the more porous microstructure of the complexes confirmed that phenolic acids could interfere with the gel structure of the starch. The addition of different phenolic acids decreased the rapidly digestible starch (RDS) content and increased the resistant starch (RS) content, with GA exhibiting the best inhibitory capacity on starch in vitro digestibility, which might be associated with the number of hydroxy groups in phenolic acids. These results revealed that phenolic acids could affect the physicochemical characteristics of PS and regulate its digestion and might be a potential choice for producing slow digestibility starch foods.

The Biotransformation of Lupine Seeds by Lactic Acid Bacteria and Penicillium camemberti into a Plant-Based Camembert Alternative, and Its Physicochemical Changes during 7 Weeks of Ripening

In recent years, there has been increasing consumer interest and research into plant-based dairy alternatives, due to the increasingly negative impact of animal products on human health, animal welfare, and the environment. The purpose of this study was to investigate the physicochemical and microbiological changes in a Camembert alternative based on the seeds of sweet lupine (Lupinus angustifolius L cv. ‘Boregine’). After heat treatment and homogenization, the seeds were incubated with lactic acid bacteria (LAB) and Penicillium camemberti mold. After fermentation at room temperature, the samples were stored at 12 °C for 14 days, and then ripened until day 49 at 6 °C. Changes in microbial population, acidity, texture, content of polyphenols, flavonoids, reducing sugars, and free amino acids were monitored. In addition, the antioxidant capacity of the samples during ripening was determined. The results showed that LAB and fungi were able to grow well in the lupine matrix. Initially, a decrease in pH was observed, while in the further stages of ripening, alkalization of the product linked with progressive proteolysis associated with an increase in free amino acid content was noted. Hydrolysis of polysaccharides and an increase in antioxidant activity were observed. This indicates the potential of lupine seeds as a raw material for the development of a new group of plant-based ripened cheese alternatives.

Bioactivity and Bioaccessibility of Bioactive Compounds in Gastrointestinal Digestion of Tomato Bagasse Extracts

A nutrient-rich diet is a key to improving the chemical signals, such as antioxidants, which modulate pathogens’ resistance in the gut and prevent diseases. A current industrial problem is the generation of undervalued by-products, such as tomato bagasse, which are rich in bioactive compounds and of commercial interest (carotenoids and phenolic compounds). This work analyzed the effect of gastrointestinal digestion on the bioactivity and bioaccessibility of carotenoids and phenolic compounds from tomato bagasse extracts. Thus, the extraction by ohmic heating (OH) technology was compared with conventional (organic solvents). The results showed that the main phenolic compounds identified by UPLC-qTOF-MS were p-coumaric acid, naringenin, and luteolin. A higher recovery index for total phenolic compounds throughout the gastrointestinal digestion was observed for OH while for carotenoids, a strong reduction after stomach conditions was observed for both extracts. Furthermore, colon-available fraction exhibited a prebiotic effect upon different Bifidobacterium and Lactobacillus, but a strain-dependent and more accentuated effect on OH. Thus, the extraction technology highly influenced bioaccessibility, with OH demonstrating a positive impact on the recovery of bioactive compounds and related health benefits, such as antioxidant, anti-hypertensive, prebiotic, and anti-inflammatory properties. Of these properties, the last is demonstrated here for the first time.